Buggy code:
, new double [ ] { 888.0 , 884.6 } , new double [ ] { 9.2 , 10.1 } , new double [ ] { 228.1 , 226.5 } , new double [ ] { 668.5 , 666.3 } , new double [ ] { 998.5 , 996.3 } , new double [ ] { 449.1 , 448.6 } , new double [ ] { 778.9 , 777.0 } , new double [ ] { 559.2 , 558.2 } , new double [ ] { 0.3 , 0.4 } , new double [ ] { 0.1 , 0.6 } , new double [ ] { 778.1 , 775.5 } , new double [ ] { 668.8 , 666.9 } , new double [ ] { 339.3 , 338.0 } , new double [ ] { 448.9 , 447.5 } , new double [ ] { 10.8 , 11.6 } , new double [ ] { 557.7 , 556.0 } , new double [ ] { 228.3 , 228.1 } , new double [ ] { 998.0 , 995.8 } , new double [ ] { 888.8 , 887.6 } , new double [ ] { 119.6 , 120.2 } , new double [ ] { 0.3 , 0.3 } , new double [ ] { 0.6 , 0.3 } , new double [ ] { 557.6 , 556.8 } , new double [ ] { 339.3 , 339.1 } , new double [ ] { 888.0 , 887.2 } , new double [ ] { 998.5 , 999.0 } , new double [ ] { 778.9 , 779.0 } , new double [ ] { 10.2 , 11.1 } , new double [ ] { 117.6 , 118.3 } , new double [ ] { 228.9 , 229.2 } , new double [ ] { 668.4 , 669.1 } , new double [ ] { 449.2 , 448.9 } , new double [ ] { 0.2 , 0.5 } } ; private double [ ] [ ] corrData = new double [ ] [ ] { new double [ ] { 101.0 , 99.2 } , new double [ ] { 100.1 , 99.0 } , new double [ ] { 100.0 , 100.0 } , new double [ ] { 90.6 , 111.6 } , new double [ ] { 86.5 , 122.2 } , new double [ ] { 89.7 , 117.6 } , new double [ ] { 90.6 , 121.1 } , new double [ ] { 82.8 , 136.0 } , new double [ ] { 70.1 , 154.2 } , new double [ ] { 65.4 , 153.6 } , new double [ ] { 61.3 , 158.5 } , new double [ ] { 62.5 , 140.6 } , new double [ ] { 63.6 , 136.2 } , new double [ ] { 52.6 , 168.0 } , new double [ ] { 59.7 , 154.3 } , new double [ ] { 59.5 , 149.0 } , new double [ ] { 61.3 , 165.5 } } ; private double [ ] [ ] infData = new double [ ] [ ] { new double [ ] { 15.6 , 5.2 } , new double [ ] { 26.8 , 6.1 } , new double [ ] { 37.8 , 8.7 } , new double [ ] { 36.4 , 8.5 } , new double [ ] { 35.5 , 8.8 } , new double [ ] { 18.6 , 4.9 } , new double [ ] { 15.3 , 4.5 } , new double [ ] { 7.9 , 2.5 } , new double [ ] { 0.0 , 1.1 } } ; private double [ ] [ ] infData2 = new double [ ] [ ] { new double [ ] { 1 , 1 } , new double [ ] { 2 , 0 } , new double [ ] { 3 , 5 } , new double [ ] { 4 , 2 } , new double [ ] { 5 , - 1 } , new double [ ] { 6 , 12 } } ; public SimpleRegressionTest ( String name ) { } public void setUp ( ) { } public static Test suite ( ) { } public void testNorris ( ) { } public void testCorr ( ) { } public void testNaNs ( ) { } public void testClear ( ) { } public void testInference ( ) throws Exception { SimpleRegression regression = new SimpleRegression ( ) ; regression . addData ( infData ) ; assertEquals ( "slope<seq2seq4repair_space>std<seq2seq4repair_space>err" , 0.011448491 , regression . getSlopeStdErr ( ) , 1.0E-10 ) ; assertEquals ( "std<seq2seq4repair_space>err<seq2seq4repair_space>intercept" , 0.286036932 , regression . getInterceptStdErr ( ) , 1.0E-8 ) ; assertEquals ( "significance" , 4.596E-7 , regression . getSignificance ( ) , 1.0E-8 ) ; assertEquals ( "slope<seq2seq4repair_space>conf<seq2seq4repair_space>interval<seq2seq4repair_space>half-width" , 0.0270713794287 , regression . getSlopeConfidenceInterval ( ) , 1.0E-8 ) ; regression = new SimpleRegression ( ) ; regression . addData ( infData2 ) ; assertEquals ( "slope<seq2seq4repair_space>std<seq2seq4repair_space>err" , 1.07260253 , regression . getSlopeStdErr ( ) , 1.0E-8 ) ; assertEquals ( "std<seq2seq4repair_space>err<seq2seq4repair_space>intercept" , 4.17718672 , regression . getInterceptStdErr ( ) , 1.0E-8 ) ; assertEquals ( "significance" , 0.261829133982 , regression . getSignificance ( ) , 1.0E-11 ) ; assertEquals ( "slope<seq2seq4repair_space>conf<seq2seq4repair_space>interval<seq2seq4repair_space>half-width" , 2.97802204827 , regression . getSlopeConfidenceInterval ( ) , 1.0E-8 ) ; assertTrue ( "tighter<seq2seq4repair_space>means<seq2seq4repair_space>wider" , ( ( regression . getSlopeConfidenceInterval ( ) ) < ( regression . getSlopeConfidenceInterval ( 0.01 ) ) ) ) ; try { <START_BUG> double x = regression . getSlopeConfidenceInterval ( 1 ) ; <END_BUG> fail ( "expecting<seq2seq4repair_space>IllegalArgumentException<seq2seq4repair_space>for<seq2seq4repair_space>alpha<seq2seq4repair_space>=<seq2seq4repair_space>1" ) ; } catch ( IllegalArgumentException ex ) { } } public void testPerfect ( ) throws Exception { } public void testPerfectNegative ( ) throws Exception { } public void testRandom ( ) throws Exception { } public void testSSENonNegative ( ) { } }

Fix:
regression . getSlopeConfidenceInterval ( 1 ) ;